


I'm the Satellite (And You're the Sky)

by coffeehousehaunt



Category: Supergirl (TV 2015)
Genre: Angsty moment, F/F, I'm not sure why all my smut seems to sprout a character moment, Little bit of angst on Alex's part over the whole foster-sibling thing, PWP, Porn with Character, Porn with Feelings, Smut, Strap-Ons, Strap-on blowjob
Language: English
Status: Completed
Published: 2016-07-24
Updated: 2016-07-24
Packaged: 2018-07-26 09:34:53
Rating: Explicit
Warnings: No Archive Warnings Apply
Chapters: 1
Words: 2,617
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/7569109
Author URL: https://archiveofourown.org/users/coffeehousehaunt/pseuds/coffeehousehaunt
Summary: <blockquote class="userstuff">
              <p>Kara still surprises Alex. </p>
<p>Semi-established relationship, but fairly early on.</p>
            </blockquote>





	I'm the Satellite (And You're the Sky)

**Author's Note:**

> Lately I've been reading a lot about the whole thing with Alex and Kara being foster siblings and how to tag it, and wanted to say that 1) I'll always try to be clear in the tags about stuff like this because it can be a squick or trigger, and that's the last thing I want to spring on someone, but also 2) It ain't incest if they aren't related, so I'm not comfortable tagging it that. 
> 
> But, 3, in my head, it is something that both of them would end up having to deal with if there's gonna be a ship.

Alex pulls the straps of the harness tight, shifting her weight on her feet slightly to accommodate the pressure, the slightly sharp dig of the harness into the skin of her hips, her thighs; the sensation of weight where there usually isn’t, no matter how light. She’s facing the drawer where they keep the strap-on, away from Kara while she takes off her Supergirl costume. 

At the end of the day, it just isn’t worth the work to make putting on a strap-on sexy. Usually, at least. Especially after a day like today. 

Mostly, they’d both like to skip to the part where they’re touching. Tangled up like they’re never going to come apart. 

Alex pushes extra length from the straps through their respective loops to secure it down—and then there's a hand on her hip, warm. Alex follows that touch, turns around to see Kara, still in her Supergirl outfit, only her boots and the cape removed, looking at her through her eyelashes. Intent and searching, biting her lip. Alex's heart stops for a moment; Alex's _everything_ stops for a moment. 

"Kara?" She asks when she can find her breath, and her voice is already soft, husky and breathless edged with the weight behind that look. 

Kara doesn't say anything, but her lips part softly, breath shivering through them. And then she sinks to her knees. 

Alex—Alex _knows_ Kara. Beyond the costume. She's known her awkward and teenaged with _really_ unfortunate hair; known her eating potstickers at midnight or 3 am. Knows that she loves math but failed her way through high school because the classes were too basic and the structure was _terrible_ (you think the American school system sucks for Americans—try being from another _planet_ )—and she was extra afraid to pass subjects she loved. The loud red and blue of the costume, in some ways, is just that—loud. 

But seeing Kara go to her knees like this— _Supergirl_ going to her knees—Alex feels dizzy. 

Kara could do what she does in sweatpants. And Alex has adored her for it since Kara talked her out of her window in a zip-hoodie and Chucks. Kara’s never needed to put on a uniform to make Alex want her. Or—hell—powers. What’s precious, what holds all the power, isn’t el mayarah, or the cape, some obscure biology that they might never unlock, or the backstory; it’s _Kara_. 

And all of that, all of _her_ , just knelt in front of Alex. 

Then she feels Kara's breath on her thigh, the hollow of her hipbone, and her eyes drift closed for a moment and her lips part, acutely aware of the length of the strap-on, the hardness of it, curving out from the front of her body. Exposed. Vulnerable, even. Her muscles tense, hold, cutting her breathing short and shallow, as Kara's thumbs trace down over her hipbones. The line between where her body ends and the dildo begins blurs and disappears proportional to Kara’s closeness. 

She _feels_ hard, like this; so close to the curve of Kara's cheek.

Kara's thumbs slip over the leather of the harness, tracing the lines of it, and then further down, to her inner thighs. The blood feels pooled almost painfully between Alex’s legs. 

Alex watches Kara's face, fixed to the spot. All that pressure seems to concentrate in the shaft of the dildo, until the thrumming of her heartbeat feels like it's echoing down it and she swears she can feel Kara's breath on it. On _her_. A muscle in Alex's hips twitches. 

And then Kara makes her decision. One of Kara's hands lingers on Alex's hip, rubbing tingling circles into the hollow there. The other reaches up to tug her hair to one side, so that it all falls over one shoulder. She tilts her head up and looks at Alex again through her eyelashes, heavy-lidded and wicked and careful and vulnerable at the same time. 

It's all Alex can do to just _look_ at her. 

And then Kara leans up—tracing her tongue along the underside of the head as she goes. Alex can see the flash of her tongue. 

A soft sound escapes Alex's lips. 

When Kara reaches the tip, she takes the head into her mouth. Alex isn't sure _how_ , but she is sure that she can feel Kara's tongue swirling around the head. 

A strangled _"Fuck"_ falls from Alex’s mouth. 

When Kara pulls back, she puts her hands on Alex's hips and guides her back, gently. It's a step and a half until she's back against the wall, the cool of it a shock on her bare back. Alex braces herself against it, eyes fluttering closed for a heartbeat. 

But then she has to look back down, just in time to see Kara take her into her mouth again. 

It’s relief and torture at the same time. She’s safe with Kara—always safe with Kara, _inside_ Kara. But so _exposed_ , like this. 

And slowly, so slowly, Kara takes her in. Inch by inch, pulling back slowly and teasing with her tongue, eyes closed and hair curtaining to one side and her lips far too perfect for how _fuckable_ she looks with her eyes closed like that. 

It's soft and reverent, but Alex watches as Kara takes more and more of it. It's all she can do, is watch and hang onto the wall. 

When the tip of Kara's nose brushes Alex's skin, Alex lets out a choked sound at the sight before her, the tightness and pressure of Kara's body around her. 

God, she can feel _everything_. Kara _holding_ that part of her—even if it isn’t _part_ of her—in the delicate structure of her throat. There's a trembling tension in her guts that feels like it could spill over at any moment. The hot rush of being _hard_ , amplified by the intimacy, the vulnerability of their position. Kara's _attention_ there. 

One of Alex's hands pulls away from the wall and sifts through Kara's hair, soft and sun-warm. A sound crawls out of Kara's throat. Alex's fingers thread through, more confident. There's more, now; Kara's mouth, the back of her throat, the curve of her head under Alex's hand. Oh, god. 

Kara moves with her. Follows her lead. Willingly. _Eagerly_. She takes Alex in, and in, until her nose brushes Alex's skin again. Alex gasps. That focused serenity on Kara's face tinges with longing. 

Alex pulls her hips back slightly. She watches Kara's face. Has to see this, can’t look away. 

Kara practically welcomes her back, her face smoothing out with pleasure. 

Shocks race through Alex's whole body when she sees how _affected_ Kara looks. Intimate and submissive and oh god, Kara _can't_ be like this, can't be like… 

This can't be what Alex has always wanted. She can want to make _love_ to Kara, but this, the complete abandon on Kara's face, it brings out something raw and primal and completely uninterested in the rightness or wrongness of wanting her _sister_ , her charge, her responsibility, on her knees, the sweet ache on her face while she takes Alex's cock down her throat, makes soft, choked sounds around it. 

That dark surges in her, her chest, her blood, floods between her legs, and Kara whimpers like she can sense it. 

Like she wants it, too. 

Alex is shaking, not sure if it's from arousal or something else. She should stop, part of her thinks, but another part of her knows—she can't un-know this. Now that she's seen it, she'll never forget it. She'll see it behind her closed eyelids. She'll see it when she's drunk. 

It's in her blood, now. Seared into every cell of her body. Or maybe it already was, and that's the reason for everything that came before. The secrets and the liquor and the drugs and the fucking and fighting. 

Alex lets her head fall back against the wall. She feels dizzy and eight kinds of disoriented. Only one of them has to do with being so turned on she can barely stand. 

"Are you okay?" Kara's voice is rough and fucked and Alex hates the part of herself that beats for it, just a little. 

"No." Alex says softly. Because lying is what got them into this in the first place. 

"D'you want to stop?" 

Alex laughs softly. "I can't." She admits, because she's tried, and she can almost hear Kara's brows furrow at the non sequitur. 

"Hey." 

Alex looks down at Kara. It's cheesy to say, but it's true; it's like staring down the sun. Kara's looking back the same, eyes bright and intent and alert—even if they are a little heavy-lidded. 

It's a relief, to step back like this. Not just to stop, but to see Kara, completely gone a few moments before, looking up at her, fully present and aware despite her disheveled state. The costume, which might've seemed a little odd before, feels calming somehow, helps her snap out of the headspace a little further. 

Not too long ago, Kara might've taken it as a rejection. Old wounds, old vulnerabilities. Sore spots that they seem so terrible at missing. 

Instead, she's looking up at Alex with complete understanding and openness, that same devotion tinged with a sadness and understanding that makes Alex's heart hurt—and Kara's not flinching. 

"I know what it's like to feel like you're ugly inside." She says softly, one eyebrow quirked in a subtle question; it firms over when the tremor in Alex’s breath confirms it. "To find parts of yourself you can't bear to look at." One thumb strokes soothingly along Alex's hipbone. "But that isn't everything you are. It isn't everything _we_ are. I _want_ you. Even like this." 

Alex lets out a shivery, rushing laugh. Her head falls back against the wall again. Everything feels impossibly light and heavy at the same time. "You always know what to say." 

The smile in Kara's voice loosens something in her chest. Alex closes her eyes and hangs onto it like a life preserver. "It's one of my superpowers." That thumb taps softly, like she's thinking. "And I know." 

Alex looks down to ask, _Know what?_. But the quirked sympathetic smile tells her everything. 

"I'm sorry." She says. This was going so well, too. 

Kara's smile spreads a little further, playfully. "Part of you is," She says, "And part of you isn't." That smile turns more serious, more earnest. "I'm going with the part of me that isn't." She’s _not_ talking about the sex. 

Alex stares down at her. Kara looks back without flinching. Part of Alex wants to drop down and cling to her. 

She's not sure which part of her she can go with. But Kara's faith is unshakable, and it steadies her. 

"I just…” Alex swallows, voice rougher than she means it to be. "I just want to be close to you." It's the euphemism she can stand. 

Kara's head tilts slightly; one eyebrow rises. Alex nods, feeling more confident. She feels broken, like something's cut her open; but paradoxically, she feels _whole_. 

Kara pulls her close, warm material of her costume scratching slightly against Alex's skin. Alex may or may not let herself cling a little bit. She'll deny it if anyone asks. 

Anyone other than Kara, that is. 

"I can hold you." Kara murmurs against her ear. 

Alex makes a sound that could be a whimper, or a moan, or a sob; or maybe all three. Kara pulls back and kisses her, soft and blisteringly hot at the same time. Alex _does_ cling, then. 

Kara kisses her slowly and thoroughly; she moves to Alex's neck, and then her collarbone, and then, so carefully, down to her knees again. Until she's looking up at Alex again, eyes going heavy-lidded. Alex feels her pulse radiating through the strap-on again. What the hell _is_ this? It's not usually so acute. 

But, she supposes, there's more to it in the context. 

"Can I try again?" Kara asks. Alex swallows hard and nods. Kara's words from earlier are comforting. _Part of you_ , she'd said. 

The whole of them is right here. Is in Kara's costume, in the way she's managed to reclaim her family's coat of arms, to wear it proudly, even; how they've managed to reclaim their bond. Not just what they’ve been given, but what they’ve made out of it. _Who_ they are, and not what. 

And if Kara wants _that_ part of her, too… They'll handle that together. Alex believes that, looking into Kara’s eyes. 

That whole train of thought goes off the rails when Kara's tongue touches the tip of Alex's cock, leaving Alex with the lingering feeling of being rent open and raw and so _tangible_ and real it's almost unbearable. Almost. 

And when she's surrounded by the heat of Kara's body again, held there, and it feels so _safe_ , covering all the rawest places, that Alex's legs tremble and she loses her breath. 

Kara really only needs a couple fingers to guide the strap-on where she wants it. Once she has that set up again, her hand wanders to Alex's inner thigh, stroking softly. And then up. And up. Until— 

Alex lets out a whimper that ends in a moan as Kara's fingers slide inside her. Soaked, some part of her notes, she's _soaked_. The muscles in her legs loosen and her hips push forward, caught between the feeling of being buried in Kara's mouth, her throat, and penetrated at the same time. She's not sure where what ends and what starts, or where the sensations are coming from or going to. There's a tension coiling low in her abdomen, in the muscles of her thighs and her ass. She’s panting like she’s running a race, but she’s clinging to the wall. Her other hand, that was tightening in Kara’s hair before, is almost slack; the muscles in it are trembling, ever so slightly. 

Kara's knuckles press against the inside of her, fingers sliding and crooking, fingertips moving in slow, strong circles, and Alex loses her rhythm completely; loses her damn _mind_ , any coherent sense of what's going on around her. There's just Kara, Kara's mouth, her fingers, and Alex clenches down and her hips feel completely _open_ and the muscles in her thighs and ass are pushing forward at the same time, the whole feeling of it leaving her body through the dildo. It feels impossibly real. 

For a moment, all Alex is, is the shivering in her skin, the rush of her breath; she hasn't lost track of herself like this in _years_. It's been a long time since she was reduced down solely to _feeling_ , unable to do anything else. 

Then, slowly, there's Kara's hands on the backs of her thighs, Kara's hands deceptively gentle, so that Alex can't quite tell if Kara's holding her up, or the wall is. Kara's hands, _Kara_ , anchoring her here. Lost and floating against her grip. 

Alex opens her eyes to Kara looking up at her, utterly steady, unshakable. 

She finds her feet again, and reaches down, guiding Kara up until she can kiss her edgeless and soft. 

The material of Kara's costume scrapes lightly on Alex's stomach, her breasts, and she pulls back and gathers a fistful of the material. 

"This needs to get out of the way." She smiles, voice husky. Kara's eyes sparkle back. The top falls to the floor first, and then the skirt. Alex presses every inch of their skin together that she can manage. 

"Bed." She pants when they come apart. Kara nods. 

When Kara draws Alex down to her, it might be for the hundredth time, but Alex loses herself all over again.

**Author's Note:**

> Title from "Cecilia and the Satellite", by Andrew McMahon.


End file.
